Manitoba Health, Seniors and Active Living (MHSAL) Influenza Surveillance Report `Week 2017 2018 53: Dec 28, 2014 Jan 3, 2015 Week 6 (Feb. 4 10, 2018) Data extracted Feb. 16, 2018 at 11:00 am Summary: Decreasing Provincial Update: The influenza activity level in Manitoba continued to decrease in Week 6 after passing the seasonal peak in Week 1. The decrease was largely due to the decreasing activity of influenza A. However, there has been sustained activity due to influenza B. This week, there was a similar number of influenza A and B detections. Together, influenza A and B accounted for only 20% of laboratory detections of all respiratory viruses in comparison to over 85% during the peak week. There has been a decreasing activity in most syndromic indicators as well. Both overall respiratory outbreaks and laboratory confirmed influenza outbreaks continued to decrease. In total, there have been 363 influenza associated hospital admissions since the beginning of this season and over 70% of those patients are aged 65 years and above. National Update: Influenza activity in Canada overall remained at peak levels in Week 5 with some indication of slowing down activity. Some provinces have passed the seasonal peak. In Week 5, the number of influenza B detections was similar to the number of influenza A detections. As well, influenza A and B accounted for an equal proportion of hospitalizations. International Update: In Week 6, influenza activity remained high in the United States. This week, majority of the states had widespread influenza activity and experienced high ILI activity. Laboratory Severity Outbreak Laboratory-confirmed influenza cases this week: Influenza A cases: 27 Influenza B cases: 28 Since Sept. 1, 2017: Influenza A cases: 1003 Influenza B cases: 166 == Severe outcomes associated with laboratory-confirmed diagnosis of influenza this week: Hospitalizations: 7 ICU* admissions: 0 Deaths: 0 Since Sept. 1, 2017: Hospitalizations: 363 ICU* admissions: 26 Deaths: 32 == Laboratory-confirmed Influenza outbreaks this week: Influenza A outbreaks: 1 Influenza B outbreaks: 0 Influenza A & B outbreaks: 0 Since Sept. 1, 2017: Influenza A outbreaks: 61 Influenza B outbreaks: 1 Influenza A & B outbreaks: 7 Syndromic in Community Syndromic in Care Syndromic in ED Calls to Influenza Service at Health Links Info Santé this week: 38 Visits to sentinel physicians due to ILI this week: 2.4% Units of antiviral dispensed from pharmacies this week: 91 Respiratory visits to Emergency Department (ED) this week: 157/day Immunization Antiviral Susceptibility Regional Health Authority As of Jan. 31, 2018: Percentage of Manitoban residents immunized with the seasonal influenza vaccine: 21.5% Isolates resistant to antiviral since Sept. 1, 2017 in Canada: Oseltamivir: 1 (out of 736 tests) Zanamivir: 1 (out of 732 tests) Influenza cases (cases/100,000 population) since Sept. 1, 2017: Winnipeg: 583 (74.8) Southern: 137 (68.2) Interlake-Eastern: 84 (65.1) Prairie Mountain: 246 (144.1) Northern: 119 (154.9) Note. * ICU admissions were also included in hospitalizations. Time trends in this report were analyzed by epidemiology week. Numbers are subject to change. Missed events in the current report due to a delay of submission to MHSAL will be included in later reports when data become available.
Week 6 (Feb. 4 10, 2018) [MHSAL Influenza Surveillance Report] 2 Figure 1. Weekly Cases of Laboratory-Confirmed Influenza, Manitoba Figure 2. Weekly Influenza and ILI Outbreaks, Manitoba
Week 6 (Feb. 4 10, 2018) [MHSAL Influenza Surveillance Report] 3 Figure 3. Weekly Influenza Related Calls to Health Link- Info Santé, Manitoba Figure 4. Weekly % of ILI Related Visits to Sentinel Physicians, Manitoba
Week 6 (Feb. 4 10, 2018) [MHSAL Influenza Surveillance Report] 4 Figure 5. Weekly Units of Antiviral Dispensed from Pharmacies, Manitoba Figure 6. Weekly Respiratory Visits to Emergency Department and % of Total, Winnipeg Regional Health Authority, Manitoba, 2017-2018
Week 6 (Feb. 4 10, 2018) [MHSAL Influenza Surveillance Report] 5 Figure 7. Weekly Total and Respiratory Visits per Day to Emergency Department, Winnipeg Regional Health Authority, Manitoba.
Week 6 (Feb. 4 10, 2018) [MHSAL Influenza Surveillance Report] 6 Table 1. Antiviral Resistance of Isolates by Influenza Type and Subtype since September 1, 2017, 2017 2018 Oseltamivir Zanamivir Amantadine Resistant Sensitive Resistant Sensitive Resistant Sensitive Canada A(H3N2) 0 390 0 386 795 0 A(H1N1) 1 59 0 60 74 0 B 0 286 1 285 N/A N/A Manitoba A(H3N2) 0 44 0 43 70 0 N/A = Not applicable A(H1N1) 0 2 0 2 2 0 B 0 7 0 7 N/A N/A Table 2. Influenza Strain Characterization reported by NML since September 1, 2017, 2017 2018 Strain Number of viruses Canada Manitoba A/Hong Kong/4801/2014 (H3N2)-like 163 22 A/Michigan/45/2015 (H1N1)-like 72 2 B/Brisbane/60/2008-like 24 0 B/Phuket/3073/2013-like 537 9 Since September 1, 2017, NML has characterized 1443 influenza A and B viruses. 1. 810 influenza A(H3N2) viruses: 163 influenza A(H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014, the influenza A(H3N2) component of the 2017-2018 Northern Hemisphere influenza vaccine. In those 163 viruses, 132 belonged to genetic group 3C.2a and 15 belonged to subclade group 3C.2a1. 15 viruses belonged to genetic clade 3C.3a. One isolates is yet to be sequenced. 647 influenza A(H3N2) viruses did not grow to sufficient hemagglutination titers for antigenic characterization by hemagglutination inhibition assays. Therefore, genetic characterization was performed. Sequence analysis of the HA gene of these viruses showed that 570 H3N2 viruses belonged to genetic group 3C.2a, 75 belonged to subclade 3C2a1 and two virus belonged to clade 3C.3a. A/Hong Kong/4801/2014(H3N2)- like virus, the vaccine strain, belongs to genetic group 3C.2a. 2. 72 influenza A(H1N1) viruses: 58 influenza A(H1N1) viruses characterized were antigenically similar to A/Michigan/45/2015, the influenza A(H1N1) component in the vaccine. 3. 561 influenza B viruses: 24 influenza B viruses were antigenically similar to B/Brisbane/60/2008-like (Victoria lineage), the influenza B component in the vaccine. 537 influenza B viruses characterized were characterized as B/Phuket/3073/2013 (Yamagata lineage), the influenza B component only in the quadrivalent vaccine.
Week 6 (Feb. 4 10, 2018) [MHSAL Influenza Surveillance Report] 7 Appendix Data Sources Laboratory Surveillance Detections of influenza nucleic acid detection, culture isolation, and enzyme immunoassay (EIA) are reported from Cadham Provincial Laboratory (CPL) and occasionally other laboratories. These reports are forwarded to Epidemiology and Surveillance (E&S) within 24 hours of confirmation. CPL also performs testing for other respiratory viruses including parainfluenza, RSV, adenovirus, rhinovirus, coronavirus, enterovirus, and bocavirus, which are reported to E&S on a weekly basis. Influenza Associated Hospitalizations, ICU Admissions and Deaths Each influenza season on a weekly basis, the Public Health Office in each Regional Health Authority (RHA) is requested to submit a line list of hospitalizations, Intensive Care Unit (ICU) admissions and deaths for laboratory-confirmed influenza patients that were admitted in hospitals in the reporting RHA or deceased as the registered residents of the reporting RHA. The reason for the hospitalizations, ICU admissions or the cause of deaths does not have to be attributable to influenza. Instead, a temporal association with a positive influenza laboratory result is sufficient due to the requirement for timely reporting. Submissions are cleaned by E&S to remove duplicate submissions for the same patient within the same illness episode. In this report, only Manitoba residents are included. Outbreak Outbreaks are reported to E&S by a phone call or email from public health staff within RHAs or from CPL advising the assignment of an outbreak code. CPL submits both positive and negative laboratory results related to outbreaks to E&S. Outbreak investigations are reported from RHAs to E&S by completing an outbreak summary report form electronically through the Canadian Network for Public Health Intelligence (CNPHI) or on paper. Health Links Info Santé Health Links Info Santé is a 24-hour, 7-days a week telephone information service. It is staffed by registered nurses with the knowledge to provide answers to health care questions and guidance to appropriate care over the phone. When a caller phones Health Links Info Santé and selects Influenza Service, they are given an option to select information on (1) the groups of individuals who are at an increased risk of serious illness, (2) how to arrange an influenza vaccine, (3) the annual influenza immunization campaign, or (4) the management of influenza and its potential complications. ILI Visits to Sentinel Physicians Manitoba participates in FluWatch, the Canada s national surveillance system co-ordinated by Public Health Agency of Canada (PHAC), which monitors the spread of influenza and ILI on a year-round basis. FluWatch consists of a network of laboratories, hospitals, doctor s offices and provincial and territorial ministries of health. In 2017 2018, there are 19 sentinel physicians recruited throughout Manitoba reporting to FluWatch weekly. E&S receives weekly reports from FluWatch which present the ILI rate for Manitoba and for each participating sentinel physician. The reporting sentinel physicians are different by week and their reports may not be representative of ILI activity across the province.
Week 6 (Feb. 4 10, 2018) [MHSAL Influenza Surveillance Report] 8 Antiviral Dispensing The units of antiviral drugs, Oseltamivir and Zanamivor, dispensed from community retail pharmacies to Manitoba residents are reported to E&S from Drug Programs Information Network (DPIN) on a weekly basis. Antiviral drugs dispensed to in-patients or through nursing stations could not be included in this report due to lack of data. Respiratory Visits to Emergency Department Daily statistics of visits to Emergency Department (ED) that are related to respiratory illness in Winnipeg Regional Health Authority (WRHA) are submitted to E&S weekly. ILI cases are defined as patients whose triage chief complaints contain either of these symptoms: weakness, shortness of breath, cough, headache, fever, cardiac/respiratory arrest, sore throat, and upper respiratory tract infection complaints. Immunization Immunization data were extracted from Panorama, the provincial immunization registry. The report includes clients who have received one or more valid doses of the influenza vaccine and who have active registration with Manitoba Health, Seniors and Active Living (MHSAL) at the time that the report is generated (i.e. it is not based on the number of doses in the registry divided by the population of Manitoba). This report coverage does not include the following: clients who have moved or passed away and are now inactive in the client registry; clients who receive services from public health in Manitoba, but have been entered in the Immunization Registry as inactive clients; clients who are not in the registry, such as immigrants and refugees, visiting students, and visitors who are not registered for health services in Manitoba; doses that have not been reported to MHSAL. Antiviral Resistance Influenza and Respiratory Viruses Section of National Microbiology Laboratory (NML) undertakes enhanced surveillance, investigations, and research on influenza and other respiratory pathogens. A sample of positive influenza specimens isolated by culture is referred from each provincial laboratory to NML for strain characterization and antiviral resistance testing. The aggregate level information is then shared with provinces and territories on a weekly basis. Circulating Strain NML antigenically characterizes influenza viruses received from Canadian laboratories year-round. In Manitoba, representative samples of influenza viruses isolated by culture, from different regions, time periods and outbreaks, is referred from CPL to NML for strain characterization. Immunization Program As per World Health Organization (WHO), all seasonal quadrivalent influenza vaccines for 2017 2018 in the northern hemisphere contain: A/Hong Kong/4801/2014 (H3N2)-like virus (in trivalent vaccine) A/Michigan/45/2015 (H1N1)pdm09-like virus (in trivalent vaccine) B/Brisbane/60/2008-like virus (in trivalent vaccine) B/Phuket/3073/2013-like virus (in quadrivalent vaccine) For the 2017 2018 influenza season, MHSAL has been allotted the quadrivalent inactivated vaccines (QIV), Fluzone Quadrivalent (Sanofi Pasteur) and FluLaval Tetra (GlaxoSmithKline), and the
Week 6 (Feb. 4 10, 2018) [MHSAL Influenza Surveillance Report] 9 quadrivalent live attenuated influenza vaccine (QLAIV) FluMist Quadrivalent (AstraZeneca), as part of the province s Publicly-Funded Seasonal Influenza Immunization Program. This year, a new seasonal influenza vaccine, Fluzone High-Dose, is offered to people 65 years of age or older that are living in long-term care facilities (LTCF) in Manitoba. This vaccine is a trivalent inactivated vaccine (TIV) and contains four times the amount of influenza virus antigen per strain compared to the standard-dose influenza vaccine. Therefore, this vaccine is expected to provide better protection against seasonal influenza than the standard-dose vaccine. Abbreviations CPL CNPHI E&S ED ICU ILI LTCF MHSAL NML PHAC RHA RSV WRHA Cadham Provincial Laboratory Canadian Network for Public Health Intelligence Epidemiology and Surveillance Emergency Department Intensive Care Unit Influenza-Like-Illness Long Term Care Facility Manitoba Health, Seniors and Active Living National Microbiology Laboratory Public Health Agency of Canada Regional Health Authority Respiratory Syncytial Virus Winnipeg Regional Health Authority Explanatory Notes and Definitions Cumulative Data Cumulative data include updates to previous weeks; due to reporting delays or amendments, the sum of weekly report totals may not add up to cumulative totals. Data Extraction Date Manitoba-specific information contained within this report is based on data confirmed at 11:00 am on the date of data extraction. Epidemiology Week Time trends in this report are presented by epidemiology week, a schedule used by the national FluWatch program coordinated by PHAC. Incidence Rate Incidence rate measures the frequency that influenza occurs in a population. It is calculated as the total number of new cases this influenza season multiplied by 100,000 and divided by the total population in each region. Regional populations are based on the Manitoba Health Population Report 2016. ILI in General Population Acute onset of respiratory illness with fever and cough and with one or more of the following sore throat, arthralgia, myalgia, or prostration, which is likely due to influenza. In children under 5, gastrointestinal symptoms may also be present. In patients under 5 or 65 and older, fever may not be prominent.
Week 6 (Feb. 4 10, 2018) [MHSAL Influenza Surveillance Report] 10 ILI Outbreak Schools: Greater than 10% absenteeism (or absenteeism that is higher (e.g. >5-10%) than expected level as determined by school or public health authority) which is likely due to ILI. Hospitals and residential institutions: Two or more cases of ILI within a seven-day period. Other settings: Two or more cases of ILI within a seven-day period, including at least one laboratory confirmed case; i.e. workplace, closed communities. Specimen Collection Date The date the laboratory specimen was taken is used to assign cases to the epidemiology week in this report. Occasionally, if the specimen collection date is not available, the laboratory report date will be used. Epidemiology and Surveillance Manitoba Health, Seniors and Active Living flusurveillance@gov.mb.ca (204)786-7335 Other Epidemiology and Surveillance reports http://www.gov.mb.ca/health/publichealth/surveillance/index.html National Influenza Surveillance http://www.phac-aspc.gc.ca/fluwatch/index-eng.php